Techniques and apparatuses for hybrid automatic repeat request acknowledgement (HARQ-ACK) feedback for carrier aggregation in new radio

ABSTRACT

Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment (UE) may determine a first hybrid automatic repeat request acknowledgement (HARQ-ACK) payload for a first component carrier (CC) set based at least in part on a first downlink assignment index (DAI). The UE may determine a second HARQ-ACK payload for a second CC set based at least in part on a second DAI. The UE may transmit the first HARQ-ACK payload for the first CC set and the second HARQ-ACK payload for the second CC set. Numerous other aspects are provided.

CROSS-REFERENCE TO RELATED APPLICATIONS UNDER 35 U.S.C. § 119

This application claims priority to U.S. Provisional Patent ApplicationNo. 62/587,981, filed on Nov. 17, 2017, entitled “TECHNIQUES ANDAPPARATUSES FOR HYBRID AUTOMATIC REPEAT REQUEST ACKNOWLEDGEMENT(HARQ-ACK) FEEDBACK FOR CARRIER AGGREGATION IN NEW RADIO,” which ishereby expressly incorporated by reference herein.

FIELD OF THE DISCLOSURE

Aspects of the present disclosure generally relate to wirelesscommunication, and more particularly to techniques and apparatuses forhybrid automatic repeat request acknowledgement (HARQ-ACK) feedback forcarrier aggregation in New Radio.

BACKGROUND

Wireless communication systems are widely deployed to provide varioustelecommunication services such as telephony, video, data, messaging,and broadcasts. Typical wireless communication systems may employmultiple-access technologies capable of supporting communication withmultiple users by sharing available system resources (e.g., bandwidth,transmit power, and/or the like). Examples of such multiple-accesstechnologies include code division multiple access (CDMA) systems, timedivision multiple access (TDMA) systems, frequency-division multipleaccess (FDMA) systems, orthogonal frequency-division multiple access(OFDMA) systems, single-carrier frequency-division multiple access(SC-FDMA) systems, time division synchronous code division multipleaccess (TD-SCDMA) systems, and Long Term Evolution (LTE).LTE/LTE-Advanced is a set of enhancements to the Universal MobileTelecommunications System (UMTS) mobile standard promulgated by theThird Generation Partnership Project (3GPP).

A wireless communication network may include a number of base stations(BSs) that can support communication for a number of user equipment(UEs). A user equipment (UE) may communicate with a base station (BS)via the downlink and uplink. The downlink (or forward link) refers tothe communication link from the BS to the UE, and the uplink (or reverselink) refers to the communication link from the UE to the BS. As will bedescribed in more detail herein, a BS may be referred to as a Node B, agNB, an access point (AP), a radio head, a transmit receive point (TRP),a new radio (NR) BS, a 5G Node B, and/or the like.

The above multiple access technologies have been adopted in varioustelecommunication standards to provide a common protocol that enablesdifferent user equipment to communicate on a municipal, national,regional, and even global level. New radio (NR), which may also bereferred to as 5G, is a set of enhancements to the LTE mobile standardpromulgated by the Third Generation Partnership Project (3GPP). NR isdesigned to better support mobile broadband Internet access by improvingspectral efficiency, lowering costs, improving services, making use ofnew spectrum, and better integrating with other open standards usingorthogonal frequency division multiplexing (OFDM) with a cyclic prefix(CP) (CP-OFDM) on the downlink (DL), using CP-OFDM and/or SC-FDM (e.g.,also known as discrete Fourier transform spread OFDM (DFT-s-OFDM)) onthe uplink (UL), as well as supporting beamforming, multiple-inputmultiple-output (MIMO) antenna technology, and carrier aggregation.However, as the demand for mobile broadband access continues toincrease, there exists a need for further improvements in LTE and NRtechnologies. Preferably, these improvements should be applicable toother multiple access technologies and the telecommunication standardsthat employ these technologies.

SUMMARY

In some aspects, a method of wireless communication may be performed bya user equipment (UE). The method may include determining a first hybridautomatic repeat request acknowledgement (HARQ-ACK) payload for a firstcomponent carrier (CC) set based at least in part on a first downlinkassignment index (DAI); determining a second HARQ-ACK payload for asecond CC set based at least in part on a second DAI; and transmittingthe first HARQ-ACK payload for the first CC set and the second HARQ-ACKpayload for the second CC set.

In some aspects, a method of wireless communication may be performed bya user equipment (UE). The method may include determining a first sizeindicator that indicates a first size of a first hybrid automatic repeatrequest acknowledgement (HARQ-ACK) payload associated with a firstcomponent carrier (CC), wherein the first size is determined based atleast in part on a first code block group (CBG) configuration for thefirst CC; determining a second size indicator that indicates a secondsize of a second HARQ-ACK payload associated with a second CC, whereinthe second size is determined based at least in part on a second CBGconfiguration for the second CC; transmitting the first size indicatorand the second size indicator in a size indicator group; andtransmitting the first HARQ-ACK payload and the second HARQ-ACK payloadin a HARQ-ACK payload group.

In some aspects, a user equipment for wireless communication may includememory and one or more processors operatively coupled to the memory. Thememory and the one or more processors may be configured to determine afirst hybrid automatic repeat request acknowledgement (HARQ-ACK) payloadfor a first component carrier (CC) set based at least in part on a firstdownlink assignment index (DAI); determine a second HARQ-ACK payload fora second CC set based at least in part on a second DAI; and transmit thefirst HARQ-ACK payload for the first CC set and the second HARQ-ACKpayload for the second CC set.

In some aspects, a user equipment for wireless communication may includememory and one or more processors operatively coupled to the memory. Thememory and the one or more processors may be configured to determine afirst size indicator that indicates a first size of a first hybridautomatic repeat request acknowledgement (HARQ-ACK) payload associatedwith a first component carrier (CC), wherein the first size isdetermined based at least in part on a first code block group (CBG)configuration for the first CC; determine a second size indicator thatindicates a second size of a second HARQ-ACK payload associated with asecond CC, wherein the second size is determined based at least in parton a second CBG configuration for the second CC; transmit the first sizeindicator and the second size indicator in a size indicator group; andtransmit the first HARQ-ACK payload and the second HARQ-ACK payload in aHARQ-ACK payload group.

In some aspects, a non-transitory computer-readable medium may store oneor more instructions for wireless communication. The one or moreinstructions, when executed by one or more processors of a userequipment, may cause the one or more processors to determine a firsthybrid automatic repeat request acknowledgement (HARQ-ACK) payload for afirst component carrier (CC) set based at least in part on a firstdownlink assignment index (DAI); determine a second HARQ-ACK payload fora second CC set based at least in part on a second DAI; and transmit thefirst HARQ-ACK payload for the first CC set and the second HARQ-ACKpayload for the second CC set.

In some aspects, a non-transitory computer-readable medium may store oneor more instructions for wireless communication. The one or moreinstructions, when executed by one or more processors of a userequipment, may cause the one or more processors to determine a firstsize indicator that indicates a first size of a first hybrid automaticrepeat request acknowledgement (HARQ-ACK) payload associated with afirst component carrier (CC), wherein the first size is determined basedat least in part on a first code block group (CBG) configuration for thefirst CC; determine a second size indicator that indicates a second sizeof a second HARQ-ACK payload associated with a second CC, wherein thesecond size is determined based at least in part on a second CBGconfiguration for the second CC; transmit the first size indicator andthe second size indicator in a size indicator group; and transmit thefirst HARQ-ACK payload and the second HARQ-ACK payload in a HARQ-ACKpayload group.

In some aspects, an apparatus for wireless communication may includemeans for determining a first hybrid automatic repeat requestacknowledgement (HARQ-ACK) payload for a first component carrier (CC)set based at least in part on a first downlink assignment index (DAI);means for determining a second HARQ-ACK payload for a second CC setbased at least in part on a second DAI; and means for transmitting thefirst HARQ-ACK payload for the first CC set and the second HARQ-ACKpayload for the second CC set.

In some aspects, an apparatus for wireless communication may includemeans for determining a first size indicator that indicates a first sizeof a first hybrid automatic repeat request acknowledgement (HARQ-ACK)payload associated with a first component carrier (CC), wherein thefirst size is determined based at least in part on a first code blockgroup (CBG) configuration for the first CC; means for determining asecond size indicator that indicates a second size of a second HARQ-ACKpayload associated with a second CC, wherein the second size isdetermined based at least in part on a second CBG configuration for thesecond CC; means for transmitting the first size indicator and thesecond size indicator in a size indicator group; and means fortransmitting the first HARQ-ACK payload and the second HARQ-ACK payloadin a HARQ-ACK payload group.

Aspects generally include a method, apparatus, system, computer programproduct, non-transitory computer-readable medium, user equipment, basestation, wireless communication device, and processing system assubstantially described herein with reference to and as illustrated bythe accompanying drawings and specification.

The foregoing has outlined rather broadly the features and technicaladvantages of examples according to the disclosure in order that thedetailed description that follows may be better understood. Additionalfeatures and advantages will be described hereinafter. The conceptionand specific examples disclosed may be readily utilized as a basis formodifying or designing other structures for carrying out the samepurposes of the present disclosure. Such equivalent constructions do notdepart from the scope of the appended claims. Characteristics of theconcepts disclosed herein, both their organization and method ofoperation, together with associated advantages will be better understoodfrom the following description when considered in connection with theaccompanying figures. Each of the figures is provided for the purpose ofillustration and description, and not as a definition of the limits ofthe claims.

BRIEF DESCRIPTION OF THE DRAWINGS

So that the manner in which the above-recited features of the presentdisclosure can be understood in detail, a more particular description,briefly summarized above, may be had by reference to aspects, some ofwhich are illustrated in the appended drawings. It is to be noted,however, that the appended drawings illustrate only certain typicalaspects of this disclosure and are therefore not to be consideredlimiting of its scope, for the description may admit to other equallyeffective aspects. The same reference numbers in different drawings mayidentify the same or similar elements.

FIG. 1 is a block diagram conceptually illustrating an example of awireless communication network, in accordance with various aspects ofthe present disclosure.

FIG. 2 is a block diagram conceptually illustrating an example of a basestation in communication with a user equipment (UE) in a wirelesscommunication network, in accordance with various aspects of the presentdisclosure.

FIGS. 3 and 4 are diagrams illustrating examples of using downlinkassignment indexes for HARQ-ACK feedback, in accordance with variousaspects of the present disclosure.

FIG. 5 is a diagram illustrating an example of HARQ-ACK feedback forcarrier aggregation in New Radio, in accordance with various aspects ofthe present disclosure.

FIG. 6 is a diagram illustrating another example of HARQ-ACK feedbackfor carrier aggregation in New Radio, in accordance with various aspectsof the present disclosure.

FIG. 7 is a diagram illustrating an example process performed, forexample, by a user equipment, in accordance with various aspects of thepresent disclosure.

FIG. 8 is a diagram illustrating another example process performed, forexample, by a user equipment, in accordance with various aspects of thepresent disclosure.

DETAILED DESCRIPTION

Various aspects of the disclosure are described more fully hereinafterwith reference to the accompanying drawings. This disclosure may,however, be embodied in many different forms and should not be construedas limited to any specific structure or function presented throughoutthis disclosure. Rather, these aspects are provided so that thisdisclosure will be thorough and complete, and will fully convey thescope of the disclosure to those skilled in the art. Based on theteachings herein one skilled in the art should appreciate that the scopeof the disclosure is intended to cover any aspect of the disclosuredisclosed herein, whether implemented independently of or combined withany other aspect of the disclosure. For example, an apparatus may beimplemented or a method may be practiced using any number of the aspectsset forth herein. In addition, the scope of the disclosure is intendedto cover such an apparatus or method which is practiced using otherstructure, functionality, or structure and functionality in addition toor other than the various aspects of the disclosure set forth herein. Itshould be understood that any aspect of the disclosure disclosed hereinmay be embodied by one or more elements of a claim.

Several aspects of telecommunication systems will now be presented withreference to various apparatuses and techniques. These apparatuses andtechniques will be described in the following detailed description andillustrated in the accompanying drawings by various blocks, modules,components, circuits, steps, processes, algorithms, and/or the like(collectively referred to as “elements”). These elements may beimplemented using hardware, software, or combinations thereof. Whethersuch elements are implemented as hardware or software depends upon theparticular application and design constraints imposed on the overallsystem.

It is noted that while aspects may be described herein using terminologycommonly associated with 3G and/or 4G wireless technologies, aspects ofthe present disclosure can be applied in other generation-basedcommunication systems, such as 5G and later, including NR technologies.

FIG. 1 is a diagram illustrating a network 100 in which aspects of thepresent disclosure may be practiced. The network 100 may be an LTEnetwork or some other wireless network, such as a 5G or NR network.Wireless network 100 may include a number of BSs 110 (shown as BS 110 a,BS 110 b, BS 110 c, and BS 110 d) and other network entities. A BS is anentity that communicates with user equipment (UEs) and may also bereferred to as a base station, a NR BS, a Node B, a gNB, a 5G node B(NB), an access point, a transmit receive point (TRP), and/or the like.Each BS may provide communication coverage for a particular geographicarea. In 3GPP, the term “cell” can refer to a coverage area of a BSand/or a BS subsystem serving this coverage area, depending on thecontext in which the term is used.

A BS may provide communication coverage for a macro cell, a pico cell, afemto cell, and/or another type of cell. A macro cell may cover arelatively large geographic area (e.g., several kilometers in radius)and may allow unrestricted access by UEs with service subscription. Apico cell may cover a relatively small geographic area and may allowunrestricted access by UEs with service subscription. A femto cell maycover a relatively small geographic area (e.g., a home) and may allowrestricted access by UEs having association with the femto cell (e.g.,UEs in a closed subscriber group (CSG)). ABS for a macro cell may bereferred to as a macro BS. ABS for a pico cell may be referred to as apico BS. A BS for a femto cell may be referred to as a femto BS or ahome BS. In the example shown in FIG. 1, a BS 110 a may be a macro BSfor a macro cell 102 a, a BS 110 b may be a pico BS for a pico cell 102b, and a BS 110 c may be a femto BS for a femto cell 102 c. ABS maysupport one or multiple (e.g., three) cells. The terms “eNB”, “basestation”, “NR BS”, “gNB”, “TRP”, “AP”, “node B”, “5G NB”, and “cell” maybe used interchangeably herein.

In some aspects, a cell may not necessarily be stationary, and thegeographic area of the cell may move according to the location of amobile BS. In some aspects, the BSs may be interconnected to one anotherand/or to one or more other BSs or network nodes (not shown) in theaccess network 100 through various types of backhaul interfaces such asa direct physical connection, a virtual network, and/or the like usingany suitable transport network.

Wireless network 100 may also include relay stations. A relay station isan entity that can receive a transmission of data from an upstreamstation (e.g., a BS or a UE) and send a transmission of the data to adownstream station (e.g., a UE or a BS). A relay station may also be aUE that can relay transmissions for other UEs. In the example shown inFIG. 1, a relay station 110 d may communicate with macro BS 110 a and aUE 120 d in order to facilitate communication between BS 110 a and UE120 d. A relay station may also be referred to as a relay BS, a relaybase station, a relay, and/or the like.

Wireless network 100 may be a heterogeneous network that includes BSs ofdifferent types, e.g., macro BSs, pico BSs, femto BSs, relay BSs, and/orthe like. These different types of BSs may have different transmit powerlevels, different coverage areas, and different impact on interferencein wireless network 100. For example, macro BSs may have a high transmitpower level (e.g., 5 to 40 Watts) whereas pico BSs, femto BSs, and relayBSs may have lower transmit power levels (e.g., 0.1 to 2 Watts).

A network controller 130 may couple to a set of BSs and may providecoordination and control for these BSs. Network controller 130 maycommunicate with the BSs via a backhaul. The BSs may also communicatewith one another, e.g., directly or indirectly via a wireless orwireline backhaul.

UEs 120 (e.g., 120 a, 120 b, 120 c) may be dispersed throughout wirelessnetwork 100, and each UE may be stationary or mobile. A UE may also bereferred to as an access terminal, a terminal, a mobile station, asubscriber unit, a station, and/or the like. A UE may be a cellularphone (e.g., a smart phone), a personal digital assistant (PDA), awireless modem, a wireless communication device, a handheld device, alaptop computer, a cordless phone, a wireless local loop (WLL) station,a tablet, a camera, a gaming device, a netbook, a smartbook, anultrabook, medical device or equipment, biometric sensors/devices,wearable devices (smart watches, smart clothing, smart glasses, smartwrist bands, smart jewelry (e.g., smart ring, smart bracelet)), anentertainment device (e.g., a music or video device, or a satelliteradio), a vehicular component or sensor, smart meters/sensors,industrial manufacturing equipment, a global positioning system device,or any other suitable device that is configured to communicate via awireless or wired medium.

Some UEs may be considered machine-type communication (MTC) or evolvedor enhanced machine-type communication (eMTC) UEs. MTC and eMTC UEsinclude, for example, robots, drones, remote devices, such as sensors,meters, monitors, location tags, and/or the like, that may communicatewith a base station, another device (e.g., remote device), or some otherentity. A wireless node may provide, for example, connectivity for or toa network (e.g., a wide area network such as Internet or a cellularnetwork) via a wired or wireless communication link. Some UEs may beconsidered Internet-of-Things (IoT) devices, and/or may be implementedas may be implemented as NB-IoT (narrowband internet of things) devices.Some UEs may be considered a Customer Premises Equipment (CPE). UE 120may be included inside a housing that houses components of UE 120, suchas processor components, memory components, and/or the like.

In general, any number of wireless networks may be deployed in a givengeographic area. Each wireless network may support a particular RAT andmay operate on one or more frequencies. A RAT may also be referred to asa radio technology, an air interface, and/or the like. A frequency mayalso be referred to as a carrier, a frequency channel, and/or the like.Each frequency may support a single RAT in a given geographic area inorder to avoid interference between wireless networks of different RATs.In some cases, NR or 5G RAT networks may be deployed.

In some aspects, two or more UEs 120 (e.g., shown as UE 120 a and UE 120e) may communicate directly using one or more sidelink channels (e.g.,without using a base station 110 as an intermediary to communicate withone another). For example, the UEs 120 may communicate usingpeer-to-peer (P2P) communications, device-to-device (D2D)communications, a vehicle-to-everything (V2X) protocol (e.g., which mayinclude a vehicle-to-vehicle (V2V) protocol, a vehicle-to-infrastructure(V2I) protocol, and/or the like), a mesh network, and/or the like. Inthis case, the UE 120 may perform scheduling operations, resourceselection operations, and/or other operations described elsewhere hereinas being performed by the base station 110.

As indicated above, FIG. 1 is provided merely as an example. Otherexamples are possible and may differ from what was described with regardto FIG. 1.

FIG. 2 shows a block diagram of a design of base station 110 and UE 120,which may be one of the base stations and one of the UEs in FIG. 1. Basestation 110 may be equipped with T antennas 234 a through 234 t, and UE120 may be equipped with R antennas 252 a through 252 r, where ingeneral T≥1 and R≥1.

At base station 110, a transmit processor 220 may receive data from adata source 212 for one or more UEs, select one or more modulation andcoding schemes (MCS) for each UE based at least in part on channelquality indicators (CQIs) received from the UE, process (e.g., encodeand modulate) the data for each UE based at least in part on the MCS(s)selected for the UE, and provide data symbols for all UEs. Transmitprocessor 220 may also process system information (e.g., for semi-staticresource partitioning information (SRPI) and/or the like) and controlinformation (e.g., CQI requests, grants, upper layer signaling, and/orthe like) and provide overhead symbols and control symbols. Transmitprocessor 220 may also generate reference symbols for reference signals(e.g., the cell-specific reference signal (CRS)) and synchronizationsignals (e.g., the primary synchronization signal (PSS) and secondarysynchronization signal (SSS)). A transmit (TX) multiple-inputmultiple-output (MIMO) processor 230 may perform spatial processing(e.g., precoding) on the data symbols, the control symbols, the overheadsymbols, and/or the reference symbols, if applicable, and may provide Toutput symbol streams to T modulators (MODs) 232 a through 232 t. Eachmodulator 232 may process a respective output symbol stream (e.g., forOFDM and/or the like) to obtain an output sample stream. Each modulator232 may further process (e.g., convert to analog, amplify, filter, andupconvert) the output sample stream to obtain a downlink signal. Tdownlink signals from modulators 232 a through 232 t may be transmittedvia T antennas 234 a through 234 t, respectively. According to variousaspects described in more detail below, the synchronization signals canbe generated with location encoding to convey additional information.

At UE 120, antennas 252 a through 252 r may receive the downlink signalsfrom base station 110 and/or other base stations and may providereceived signals to demodulators (DEMODs) 254 a through 254 r,respectively. Each demodulator 254 may condition (e.g., filter, amplify,downconvert, and digitize) a received signal to obtain input samples.Each demodulator 254 may further process the input samples (e.g., forOFDM and/or the like) to obtain received symbols. A MIMO detector 256may obtain received symbols from all R demodulators 254 a through 254 r,perform MIMO detection on the received symbols if applicable, andprovide detected symbols. A receive processor 258 may process (e.g.,demodulate and decode) the detected symbols, provide decoded data for UE120 to a data sink 260, and provide decoded control information andsystem information to a controller/processor 280. A channel processormay determine reference signal received power (RSRP), received signalstrength indicator (RSSI), reference signal received quality (RSRQ),channel quality indicator (CQI), and/or the like.

On the uplink, at UE 120, a transmit processor 264 may receive andprocess data from a data source 262 and control information (e.g., forreports comprising RSRP, RSSI, RSRQ, CQI, and/or the like) fromcontroller/processor 280. Transmit processor 264 may also generatereference symbols for one or more reference signals. The symbols fromtransmit processor 264 may be precoded by a TX MIMO processor 266 ifapplicable, further processed by modulators 254 a through 254 r (e.g.,for DFT-s-OFDM, CP-OFDM, and/or the like), and transmitted to basestation 110. At base station 110, the uplink signals from UE 120 andother UEs may be received by antennas 234, processed by demodulators232, detected by a MIMO detector 236 if applicable, and furtherprocessed by a receive processor 238 to obtain decoded data and controlinformation sent by UE 120. Receive processor 238 may provide thedecoded data to a data sink 239 and the decoded control information tocontroller/processor 240. Base station 110 may include communicationunit 244 and communicate to network controller 130 via communicationunit 244. Network controller 130 may include communication unit 294,controller/processor 290, and memory 292.

In some aspects, one or more components of UE 120 may be included in ahousing. Controller/processor 240 of base station 110,controller/processor 280 of UE 120, and/or any other component(s) ofFIG. 2 may perform one or more techniques associated with HARQ-ACKfeedback for carrier aggregation in New Radio, as described in moredetail elsewhere herein. For example, controller/processor 240 of basestation 110, controller/processor 280 of UE 120, and/or any othercomponent(s) of FIG. 2 may perform or direct operations of, for example,process 700 of FIG. 7, process 800 of FIG. 8, and/or other processes asdescribed herein. Memories 242 and 282 may store data and program codesfor base station 110 and UE 120, respectively. A scheduler 246 mayschedule UEs for data transmission on the downlink and/or uplink.

In some aspects, UE 120 may include means for determining a first hybridautomatic repeat request acknowledgement (HARQ-ACK) payload for a firstcomponent carrier (CC) set based at least in part on a first downlinkassignment index (DAI); means for determining a second HARQ-ACK payloadfor a second CC set based at least in part on a second DAI; means fortransmitting the first HARQ-ACK payload for the first CC set and thesecond HARQ-ACK payload for the second CC set; and/or the like.Additionally, or alternatively, UE 120 may include means for determininga first size indicator that indicates a first size of a first hybridautomatic repeat request acknowledgement (HARQ-ACK) payload associatedwith a first component carrier (CC), wherein the first size isdetermined based at least in part on a first code block group (CBG)configuration for the first CC; means for determining a second sizeindicator that indicates a second size of a second HARQ-ACK payloadassociated with a second CC, wherein the second size is determined basedat least in part on a second CBG configuration for the second CC; meansfor transmitting the first size indicator and the second size indicatorin a size indicator group; means for transmitting the first HARQ-ACKpayload and the second HARQ-ACK payload in a HARQ-ACK payload group;and/or the like. In some aspects, such means may include one or morecomponents of UE 120 described in connection with FIG. 2.

As indicated above, FIG. 2 is provided merely as an example. Otherexamples are possible and may differ from what was described with regardto FIG. 2.

In New Radio, a transport block (TB) may be divided into multiple codeblock groups (CBGs), where each CBG represents a portion of thetransport block for which a receiver sends an individual acknowledgement(ACK) or negative acknowledgement (NACK). For example, if a TB includes8 CBGs, then a HARQ-ACK payload (e.g., also referred to as HARQ-ACKfeedback) for the TB may include 8 bits, one for each CBG in the TB. Thebits carried in a single CBG are acknowledged or negatively acknowledgedas a group, and bits in different CBGs are acknowledged or negativelyacknowledged separately. In this way, if a large-sized TB experiences afailure in a small number of bits, individual CBGs that include thosebits can be retransmitted instead of retransmitting the entire TB,thereby conserving network resources.

In some cases, different component carriers (CCs), used for carrieraggregation, may have different CBG configurations. For example, a firstCC may have CBGs enabled (e.g., may use per-CBG HARQ-ACK payload), and asecond CC may have CBGs disabled (e.g., may use per-TB HARQ-ACKpayload). Furthermore, when CBGs are enabled, different CCs may usedifferent numbers of CBGs per TB. This may make decoding and/orinterpretation of HARQ-ACK payload difficult, as it may be unclear whichbits of the HARQ-ACK payload correspond to which CBGs and/or TBs,especially when all HARQ-ACK payload is transmitted via a single CC(e.g., a primary CC) and/or using a single channel (e.g., a physicaluplink control channel (PUCCH) and/or a physical uplink shared channel(PUSCH)), as is often the case.

In some cases, devices communicating using carrier aggregation maydetermine the maximum number of bits that could be included in aninstance of HARQ-ACK payload, and may include that maximum number ofbits in all instances of HARQ-ACK payload across all CCs. For example,if a first CC has CBGs disabled and has a HARQ-ACK payload size of 1bit, and a second CC has CBGs enabled and has a HARQ-ACK payload size of8 bits, then the devices may use a HARQ-ACK payload size of 8 bits onboth the first CC and the second CC. However, this may result in wastedbits (e.g., 7 wasted bits per HARQ-ACK payload on the first CC) and highoverhead, thereby reducing efficiency of network communications. Sometechniques and apparatuses described herein conserve network resourcesused for HARQ-ACK payloads in carrier aggregation when different CCshave different CBG configurations.

FIG. 3 is a diagram illustrating an example 300 of using downlinkassignment indexes for HARQ-ACK feedback, in accordance with variousaspects of the present disclosure.

In LTE, the concept of a downlink assignment index (DAI) has beenproposed to solve the many-to-one mapping problem of HARQ ACK/NACKfeedback. Specifically, the DAI is designed to alleviate the ambiguitybetween the base station 110 and the UE 120 regarding the total size andindex of scheduled TBs in a single PUCCH transmission. Two DCI fieldsare introduced: a DAI counter (sometimes referred to herein ascumulative DAI) and a total DAI value, each with two bits. Asillustrated in FIG. 3, the DAI counter accumulates in a frequency firstand time second fashion. The UE 120 treats missing values in an observedDAI sequence as missing a grant and reports NACK in the PUCCH feedback.With a 2-bit modulo-4 DAI counter, the scheme is robust to anyconsecutive three missing grants, and with a 2-bit total DAI field, theissue of PUCCH payload size ambiguity caused by missing the last fewgrants is alleviated.

NR presents several challenges in the design of a robust HARQ-ACKfeedback mechanism, one of them being that the number of CBGs for eachdownlink assignment could be different, leading to potentially differentACK/NACK payload sizes across slots/CCs.

As indicated above, FIG. 3 is provided as an example. Other examples arepossible and may differ from what was described with respect to FIG. 3.

FIG. 4 is a diagram illustrating another example 400 of using downlinkassignment indexes for HARQ-ACK feedback, in accordance with variousaspects of the present disclosure.

NR supports CBG based retransmission, where the number of CBGs can beRRC configured. With LTE's DAI design, even though the UE 120 can detectmissing grants, the UE 120 cannot infer the expected ACK/NACK payloadsize for the missing grants. To solve this issue, techniques andapparatuses described herein use multiple DAI instances, one for eachACK/NACK payload size.

FIG. 4 illustrates the multiple DAI instance proposal, where CC1 and CC4are configured with TB-based retransmission, and CC2 and CC3 areconfigured with CBG-based retransmission with the number of CBGs per TBequal to 4. Note that slot 2 in CC3 is labeled as TB-based because thebase station 110 may use fallback DCI for a particular slot to indicateTB-based transmission even though the component carrier has CBGs enabledby default.

As indicated above, FIG. 4 is provided as an example. Other examples arepossible and may differ from what was described with respect to FIG. 4.

FIG. 5 is a diagram illustrating an example 500 of HARQ-ACK feedback forcarrier aggregation in New Radio, in accordance with various aspects ofthe present disclosure.

As shown in FIG. 5, a UE 120 and a base station 110 may communicateusing carrier aggregation, with five components carriers (CCs) shown asan example (e.g., CC0, CC1, CC2, CC3, and CC4). In some aspects,different CCs may have different CBG configurations. For example, one CCmay have CBGs enabled (e.g., may use per-CBG HARQ-ACK payload), andanother CC may have CBGs disabled (e.g., may use per-TB HARQ-ACKpayload). As an example, and as shown by reference number 505, CBGs maybe disabled on CC0 and CC4, and CBGs may be enabled on CC1, CC2, andCC3. Furthermore, when CBGs are enabled, different CCs may use differentnumbers of CBGs per TB.

As shown by reference number 510, the UE 120 may assign different CCs todifferent CC sets when the CCs have different CBG configurations. Forexample, one or more first CCs having CBGs disabled, such as CC0 andCC4, may be assigned to a first CC set, and one or more second CCshaving CBGs enabled, such as CC1, CC2, and CC3, may be assigned to asecond CC set. In some aspects, a CC may correspond to a downlink dataallocation (e.g., a physical downlink shared channel (PDSCH)allocation), and a CC set may correspond to a per-slot, per-CC downlinkdata allocation.

In some aspects, the UE 120 may determine a CBG configuration for a CCbased at least in part on a default or semi-static CBG configuration forthe CC. In some aspects, the default or semi-static CBG configurationmay be signaled to the UE 120, by the base station 110, in a radioresource control (RRC) configuration message, in a system informationblock (SIB), and/or the like.

In some aspects, the UE 120 may determine a CBG configuration for a CCbased at least in part on a dynamic CBG configuration for the CC. Insome aspects, the dynamic CBG configuration may be signaled to the UE120, by the base station 110, in downlink control information (DCI),such as a downlink grant and/or the like. In some aspects, the dynamicCBG configuration may override the default or semi-static CBGconfiguration. For example, a CC may have CBGs enabled by default, but adownlink grant may instruct the UE 120 to disable CBGs for one or moredownlink assignments indicated in the downlink grant. In some aspects,DCI that instructs the UE 120 to disable CBGs may be referred to asfallback DCI.

In some aspects, the assignment of CCs to CC sets may apply for aparticular transmission time interval (TTI) and/or a particular set ofTTIs. In some aspects, the TTI may be a slot, a subframe, a frame,and/or the like. For example, because a CBG configuration of a CC may beoverridden for one or more downlink assignments in one or more slots,the CBG configuration for a CC may change across different slots. Thus,CCs may be assigned to CC sets for particular slots.

In some aspects, the UE 120 may assign CCs to CC sets based at least inpart on a determination that at least one CC, to be used by the UE 120for carrier aggregation, has CBGs enabled. Additionally, oralternatively, the UE 120 may assign CCs to CC sets based at least inpart on a determination that at least two CCs, to be used by the UE 120for carrier aggregation, have different CBG configurations. For example,if all CCs used by the UE 120 have the same CBG configuration (e.g.,CBGs are disabled for all CCs, all CCs use 8 CBGs per TB, and/or thelike), then there may not be a need to assign CCs to different CC sets.

As shown by reference number 515, the UE 120 may determine differentHARQ-ACK payloads for different CC sets using different downlinkassignment indexes (DAIs) corresponding to the different CC sets. Forexample, a first DAI may be used to count a number of downlinkassignments for the UE 120 on first CC(s) included in the first CC set,and a second DAI may be used to count a number of downlink assignmentsfor the UE 120 on second CC(s) included in the second CC set. The UE 120may determine a first HARQ-ACK payload for the first CC set using thefirst DAI to identify downlink assignments on the first CC set that weresuccessfully received by the UE 120 and/or to identify downlinkassignments on the first CC set that were not successfully received bythe UE 120. Similarly, the UE 120 may determine a second HARQ-ACKpayload for the second CC set using the second DAI to identify downlinkassignments on the second CC set that were successfully received by theUE 120 and/or to identify downlink assignments on the second CC set thatwere not successfully received by the UE 120.

For example, the UE 120 may use the respective DAIs to generaterespective HARQ-ACK payloads for the different CCs. Each bit of HARQ-ACKpayload for a CC set may indicate whether a particular CBG wassuccessfully received on the CC set (e.g., in the case where CBGs areenabled for the CC set) or may indicate whether a particular TB wassuccessfully received on the CC set (e.g., in the case where CBGs aredisabled for the CC set).

In some aspects, the DAI (e.g., the first DAI and the second DAI) mayinclude a cumulative DAI (e.g., first cumulative DAI and secondcumulative DAI). A cumulative DAI may include a counter, included ineach downlink assignment (e.g., downlink grant), that is incremented bythe base station 110 for each downlink assignment scheduled for the UE120. Thus, the cumulative DAI may indicate a number of HARQ-ACK payloadsthat are to be transmitted by the UE 120. In some aspects, the basestation 110 may indicate the last two bits (e.g., the two leastsignificant bits) of the DAI to the UE 120 in DCI (e.g., in a downlinkgrant). In some aspects, such as in time division duplexing (TDD), thecumulative DAI may be incremented in a frequency-first (e.g., perfrequency resource) time-second (e.g., per time resource) manner. Insome aspects, such as in frequency division duplexing (FDD), thecumulative DAI may be incremented per carrier index. In this case, thebase station 110 and the UE 120 may use different counters to keep trackof a number of downlink assignments scheduled for the UE 120 ondifferent CC sets.

In some aspects, the DAI (e.g., the first DAI and the second DAI) mayinclude a total DAI (e.g., first total DAI and second total DAI). Atotal DAI may indicate a number of scheduled downlink assignments acrossserving cells up to the current TTI (e.g., slot, subframe, and/or thelike). Thus, the total DAI may indicate a number of HARQ-ACK payloadsthat are to be transmitted by the UE 120.

As shown by reference number 520, the UE 120 may transmit, and the basestation 110 may receive, the different HARQ-ACK payloads, correspondingto the different CC sets, in different groups. For example, the UE 120may transmit a first HARQ-ACK payload, corresponding to the first CC setand generated using the first DAI, in a first group, and may transmit asecond HARQ-ACK payload, corresponding to the second CC set andgenerated using the second DAI, in a second group.

As an example, and as shown, a first group of bits may include a payloadfor CC0 and a payload for CC4, which are both included in the first CCset with CBGs disabled. In this case, since CBGs are disabled, the sizeof each HARQ-ACK payload is one bit (e.g., one bit for each TB). Asfurther shown, a second group of bits may include a payload for CC1, apayload for CC2, and a payload for CC3, which are all included in thesecond CC set with CBGs enabled. In this case, CBGs are enabled with aconfiguration of 8 CBGs per TB, so the size of each HARQ-ACK payload is8 bits (e.g., one bit for each of the 8 CBGs in a TB).

In some aspects, the UE 120 may separately concatenate HARQ-ACK payloadscorresponding to different CC sets (e.g., to form separate HARQ-ACKpayload groups), and may then concatenate all HARQ-ACK payloads togetherfor transmission to the base station 110. In some aspects, the UE 120may apply DAI padding to a HARQ-ACK payload group prior to concatenationwith other HARQ-ACK payload groups. For example, the UE 120 may applyDAI padding to form a HARQ-ACK payload group of a particular size (e.g.,a size corresponding to a multiple of M grants, such as M=4).

For example, the UE 120 may concatenate first HARQ-ACK payload for afirst CC set (e.g., for multiple CCs in the first CC set) to form afirst HARQ-ACK payload group, and may separately concatenate secondHARQ-ACK payload for the second CC set (e.g., for multiple CCs in thesecond CC set) to form a second HARQ-ACK payload group. The UE 120 maythen concatenate bits of the first HARQ-ACK payload group with bits ofthe second HARQ-ACK payload group with one another. In some aspects,prior to concatenating the bits of the first HARQ-ACK payload group withthe bits of the second HARQ-ACK payload group, the UE 120 may apply DAIpadding to the bits of the first HARQ-ACK payload group and/or the bitsof the second HARQ-ACK payload group (e.g., according to one or more DAIpadding rules).

In some aspects, the base station 110 may use the first DAI to determinethe number of HARQ-ACK payloads that are included in the first group,and may use the second DAI to determine the number of HARQ-ACK payloadsthat are included in the second group, thereby creating a clearcorrespondence between bits of HARQ-ACK payload and corresponding CBGsand/or TBs and reducing decoding errors, while conserving networkresources used for HARQ-ACK payloads in carrier aggregation whendifferent CCs have different CBG configurations (e.g., as compared tousing a maximum HARQ-ACK payload size across all CCs).

While two groups of HARQ-ACK payloads are shown as an example, in someaspects, more than two groups may be used. For example, differentnumbers of CBGs per TB may be used across different CCs. For example, aset of CCs may use 2 CBGs per TB, 8 CBGs per TB, 16 CBGs per TB, and/orthe like. In this case, CCs with different numbers of CBGs per TB may beassigned to different CC sets that use different DAIs. DifferentHARQ-ACK payload (e.g., of different sizes, such as 2 bits, 8 bits, 16bits, and/or the like) may be generated using the different DAIs, andmay be grouped separately by the UE 120 for transmission to the basestation 110.

Furthermore, while some aspects are described herein with respect toassigning CCs to different CC sets based at least in part on the CCshaving different CBG configurations, in some aspects, the CCs may beassigned to different CC sets for a different reason. For example, afirst CC set may include one or more CCs served by a first base station110, and a second CC set may include one or more CCs served by a secondbase station 110. In this case, a single base station 110 may not beable to communicate using all CCs, so separate DAIs may be maintainedfor the different CC sets.

As indicated above, FIG. 5 is provided as an example. Other examples arepossible and may differ from what was described with respect to FIG. 5.

FIG. 6 is a diagram illustrating another example 600 of HARQ-ACKfeedback for carrier aggregation in New Radio, in accordance withvarious aspects of the present disclosure.

As shown in FIG. 6, a UE 120 and a base station 110 may communicateusing carrier aggregation, with three components carriers (CCs) shown asan example (e.g., CC0, CC1, and CC2). As described above in connectionwith FIG. 5, different CCs may have different CBG configurations. Forexample, one CC may have CBGs enabled (e.g., may use per-CBG HARQ-ACKpayload), and another CC may have CBGs disabled (e.g., may use per-TBHARQ-ACK payload). Furthermore, when CBGs are enabled, different CCs mayuse different numbers of CBGs per TB. As an example, and as shown byreference number 605, CBGs may be disabled on CC0, and CBGs may beenabled on CC1 and CC2.

As shown by reference number 610, the UE 120 may determine differentsize indicators for HARQ-ACK payloads of different CCs when the CCs havedifferent CBG configurations. In some aspects, the UE 120 may determinea CBG configuration for a CC based at least in part on a semi-static(e.g., default) and/or dynamic CBG configuration for the CC, and/or maydetermine a CBG configuration for a CC for a particular set of TTIs, asdescribed above in connection with FIG. 5. A size indicator for a CC mayindicate a size of a HARQ-ACK payload for the CC, which may depend on aCBG configuration for the CC. For example, a CC with CBGs disabled mayhave a HARQ-ACK payload of one bit, a CC that uses two CBGs per TB mayhave a HARQ-ACK payload of two bits, a CC that uses eight CBGs per TBmay have a HARQ-ACK payload of eight bits, a CC that uses sixteen CBGsper TB may have a HARQ-ACK payload of sixteen bits, and/or the like.

In some aspects, the UE 120 may determine different size indicatorvalues for different size indicators only if the corresponding CCs havedifferent CBG configurations. Thus, if a first CC and a second CC havethe same CBG configuration (e.g., both have CBGs disabled, or both haveCBGs enabled with the same number of CBGs per TB), then a first sizeindicator for the first CC may have the same value as a second sizeindicator for the second CC. Additionally, or alternatively, the UE 120may use a maximum size of HARQ-ACK payloads across all CCs as a size forall HARQ-ACK payloads for all CCs.

For example, the UE 120 may determine a first size indicator thatindicates a first size of a first HARQ-ACK payload associated with afirst CC, such as CC0. In some aspects, the UE 120 may determine thefirst size indicator based at least in part on a first CBG configurationassociated with the first CC. In this case, since CBGs are disabled forCC0, the size indicator may indicate a size of one bit for HARQ-ACKpayload associated with CC0.

As another example, the UE 120 may determine a second size indicatorthat indicates a second size of a second HARQ-ACK payload associatedwith a second CC, such as CC1. In some aspects, the UE 120 may determinethe second size indicator based at least in part on a second CBGconfiguration associated with the second CC. In this case, since CBGsare enabled for CC0, the size indicator may indicate a size of, forexample, two bits, eight bits, sixteen bits, and/or the like forHARQ-ACK payload associated with CC1, depending on the number of CBGsused per TB on CC1 (e.g., two eight, sixteen, and/or the like). The UE120 may determine a third size indicator for the third CC in a similarmanner as the second CC. While three CCs are shown as an example, insome aspects, a different number of CCs may be used for carrieraggregation of communications between the base station 110 and the UE120.

As shown by reference numbers 615 and 620, the UE 120 may combine thesize indicators to form a size indicator group, and may transmit thesize indicator group to the base station 110. Similarly, as shown byreference numbers 625 and 630, the UE 120 may combine the HARQ-ACKpayloads to form a HARQ-ACK payload group, and may transmit the HARQ-ACKpayload group to the base station 110. Reference number 615 shows anexample of a one bit size indicator (shown as SI), which is capable ofdifferentiating between two different sizes of HARQ-ACK payload (shownas PL), as shown by reference number 625 (e.g., 2 bits or 16 bits).Reference number 620 shows an example of a two bit size indicator, whichis capable of differentiating between four different sizes of HARQ-ACKpayload, as shown by reference number 630 (e.g., 1 bit, 2 bits, 8 bits,or 16 bits).

In some aspects, the UE 120 may separately encode the size indicatorgroup and the HARQ-ACK payload group. Additionally, or alternatively,the UE 120 may transmit the size indicator group before the HARQ-ACKpayload group. In this way, as shown by reference number 635, the basestation 110 may interpret bits of the HARQ-ACK payload group based atleast in part on first decoding bits of the size indicator group.

For example, and referring to reference numbers 615 and 625 where thesize indicator is one bit in length, if the first bit of the sizeindicator group (e.g., which corresponds to CC0) has a value of 0, thenthe base station 110 may determine that the first HARQ-ACK payload,corresponding to CC0, is 2 bits in length. Similarly, if the second bitof the size indicator group (e.g., which corresponds to CC1) has a valueof 1, then the base station 110 may determine that the second HARQ-ACKpayload, corresponding to CC1, is 16 bits in length. The base stationmay make similar determinations regarding the size of HARQ-ACK payloadscorresponding to different CCs using the size indicators included in thesize indicator group. In this way, the base station 110 may properlyinterpret HARQ-ACK feedback and reduce errors.

As indicated above, FIG. 6 is provided as an example. Other examples arepossible and may differ from what was described with respect to FIG. 6.

FIG. 7 is a diagram illustrating an example process 700 performed, forexample, by a UE, in accordance with various aspects of the presentdisclosure. Example process 700 is an example where a UE (e.g., UE 120and/or the like) performs operations relating to HARQ-ACK feedback forcarrier aggregation in New Radio.

As shown in FIG. 7, in some aspects, process 700 may include determininga first hybrid HARQ-ACK payload for a first CC set based at least inpart on a first DAI (block 710). For example, the UE (e.g., usingcontroller/processor 280 and/or the like) may determine a first hybridHARQ-ACK payload for a first CC set based at least in part on a firstDAI, as described above in connection with FIG. 5.

As further shown in FIG. 7, in some aspects, process 700 may includedetermining a second HARQ-ACK payload for a second CC set based at leastin part on a second DAI (block 720). For example, the UE (e.g., usingcontroller/processor 280 and/or the like) may determine a second hybridHARQ-ACK payload for a second CC set based at least in part on a secondDAI, as described above in connection with FIG. 5. In some aspects, thesecond DAI may be different from the first DAI.

As further shown in FIG. 7, in some aspects, process 700 may includetransmitting the first HARQ-ACK payload for the first CC set and thesecond HARQ-ACK payload for the second CC set (block 730). For example,the UE (e.g., using controller/processor 280, transmit processor 264, TXMIMO processor 266, MOD 254, antenna 252, and/or the like) may transmitthe first HARQ-ACK payload for the first CC set and the second HARQ-ACKpayload for the second CC set, as described above in connection withFIG. 5.

Process 700 may include additional aspects, such as any single aspect orany combination of aspects described below and/or in connection with oneor more processes described herein.

In some aspects, one or more first CCs included in the first CC set areassociated with a first code block group (CBG) configuration, and one ormore second CCs included in the second CC set are associated with asecond CBG configuration that is different from the first CBGconfiguration. In some aspects, the first CBG configuration is aconfiguration where CBGs are enabled and the second CBG configuration isa configuration where CBGs are disabled.

In some aspects, at least one CC is assigned to the first CC set or thesecond CC set based at least in part on a semi-static CBG configurationfor the at least one CC. In some aspects, at least one CC is assigned tothe first CC set or the second CC set based at least in part on adynamic CBG configuration, for the at least one CC, indicated indownlink control information. In some aspects, the downlink controlinformation is fallback downlink control information that overrides adefault or semi-static code block group configuration. In some aspects,one or more first CCs are assigned to the first CC set and one or moresecond CCs are assigned to the second CC set for a particulartransmission time interval. In some aspects, one or more first CCs areassigned to the first CC set and one or more second CCs are assigned tothe second CC set based at least in part on a determination that CBGsare enabled for at least one CC of the UE.

In some aspects, the first DAI is a first cumulative DAI and the secondDAI is a second cumulative DAI. In some aspects, the first DAI is afirst total DAI and the second DAI is a second total DAI.

In some aspects, the first HARQ-ACK payload for the first CC set isconcatenated in a first HARQ-ACK payload group and the second HARQ-ACKpayload for the second CC set is concatenated in a second HARQ-ACKpayload group. In some aspects, the first HARQ-ACK payload group and thesecond HARQ-ACK payload group are concatenated with one another fortransmission. In some aspects, at least one of the first HARQ-ACKpayload group or the second HARQ-ACK payload group is padded with DAIpadding prior to concatenation with one another.

Although FIG. 7 shows example blocks of process 700, in some aspects,process 700 may include additional blocks, fewer blocks, differentblocks, or differently arranged blocks than those depicted in FIG. 7.Additionally, or alternatively, two or more of the blocks of process 700may be performed in parallel.

FIG. 8 is a diagram illustrating another example process 800 performed,for example, by a UE, in accordance with various aspects of the presentdisclosure. Example process 800 is an example where a UE (e.g., UE 120and/or the like) performs operations relating to HARQ-ACK feedback forcarrier aggregation in New Radio.

As shown in FIG. 8, in some aspects, process 800 may include determininga first size indicator that indicates a first size of a first HARQ-ACKpayload associated with a first CC, wherein the first size is determinedbased at least in part on a first CBG configuration for the first CC(block 810). For example, the UE (e.g., using controller/processor 280and/or the like) may determine a first size indicator that indicates afirst size of a first HARQ-ACK payload associated with a first CC, asdescribed above in connection with FIG. 6. In some aspects, the firstsize is determined based at least in part on a first CBG configurationfor the first CC.

As further shown in FIG. 8, in some aspects, process 800 may includedetermining a second size indicator that indicates a second size of asecond HARQ-ACK payload associated with a second CC, wherein the secondsize is determined based at least in part on a second CBG configurationfor the second CC (block 820). For example, the UE (e.g., usingcontroller/processor 280 and/or the like) may determine a second sizeindicator that indicates a second size of a second HARQ-ACK payloadassociated with a second CC, as described above in connection with FIG.6. In some aspects, the second size is determined based at least in parton a second CBG configuration for the second CC.

As further shown in FIG. 8, in some aspects, process 800 may includetransmitting the first size indicator and the second size indicator in asize indicator group (block 830). For example, the UE (e.g., usingcontroller/processor 280, transmit processor 264, TX MIMO processor 266,MOD 254, antenna 252, and/or the like) may transmit the first sizeindicator and the second size indicator in a size indicator group, asdescribed above in connection with FIG. 6.

As further shown in FIG. 8, in some aspects, process 800 may includetransmitting the first HARQ-ACK payload and the second HARQ-ACK payloadin a HARQ-ACK payload group (block 840). For example, the UE (e.g.,using controller/processor 280, transmit processor 264, TX MIMOprocessor 266, MOD 254, antenna 252, and/or the like) may transmit thefirst HARQ-ACK payload and the second HARQ-ACK payload in a HARQ-ACKpayload group, as described above in connection with FIG. 6.

Process 800 may include additional aspects, such as any single aspect orany combination of aspects described below and/or in connection with oneor more processes described herein.

In some aspects, the size indicator group is encoded separately from theHARQ-ACK payload group. In some aspects, the size indicator group istransmitted before the HARQ-ACK payload group. In some aspects, decodedbits of the HARQ-ACK payload group are interpreted based at least inpart on decoded bits of the size indicator group.

Although FIG. 8 shows example blocks of process 800, in some aspects,process 800 may include additional blocks, fewer blocks, differentblocks, or differently arranged blocks than those depicted in FIG. 8.Additionally, or alternatively, two or more of the blocks of process 800may be performed in parallel.

The foregoing disclosure provides illustration and description, but isnot intended to be exhaustive or to limit the aspects to the preciseform disclosed. Modifications and variations are possible in light ofthe above disclosure or may be acquired from practice of the aspects.

As used herein, the term component is intended to be broadly construedas hardware, firmware, or a combination of hardware and software. Asused herein, a processor is implemented in hardware, firmware, or acombination of hardware and software.

Some aspects are described herein in connection with thresholds. As usedherein, satisfying a threshold may refer to a value being greater thanthe threshold, greater than or equal to the threshold, less than thethreshold, less than or equal to the threshold, equal to the threshold,not equal to the threshold, and/or the like.

It will be apparent that systems and/or methods, described herein, maybe implemented in different forms of hardware, firmware, or acombination of hardware and software. The actual specialized controlhardware or software code used to implement these systems and/or methodsis not limiting of the aspects. Thus, the operation and behavior of thesystems and/or methods were described herein without reference tospecific software code—it being understood that software and hardwarecan be designed to implement the systems and/or methods based, at leastin part, on the description herein.

Even though particular combinations of features are recited in theclaims and/or disclosed in the specification, these combinations are notintended to limit the disclosure of possible aspects. In fact, many ofthese features may be combined in ways not specifically recited in theclaims and/or disclosed in the specification. Although each dependentclaim listed below may directly depend on only one claim, the disclosureof possible aspects includes each dependent claim in combination withevery other claim in the claim set. A phrase referring to “at least oneof” a list of items refers to any combination of those items, includingsingle members. As an example, “at least one of: a, b, or c” is intendedto cover a, b, c, a-b, a-c, b-c, and a-b-c, as well as any combinationwith multiples of the same element (e.g., a-a, a-a-a, a-a-b, a-a-c,a-b-b, a-c-c, b-b, b-b-b, b-b-c, c-c, and c-c-c or any other ordering ofa, b, and c).

No element, act, or instruction used herein should be construed ascritical or essential unless explicitly described as such. Also, as usedherein, the articles “a” and “an” are intended to include one or moreitems, and may be used interchangeably with “one or more.” Furthermore,as used herein, the terms “set” and “group” are intended to include oneor more items (e.g., related items, unrelated items, a combination ofrelated and unrelated items, and/or the like), and may be usedinterchangeably with “one or more.” Where only one item is intended, theterm “one” or similar language is used. Also, as used herein, the terms“has,” “have,” “having,” and/or the like are intended to be open-endedterms. Further, the phrase “based on” is intended to mean “based, atleast in part, on” unless explicitly stated otherwise.

What is claimed is:
 1. A method of wireless communication performed by auser equipment (UE), comprising: determining a first hybrid automaticrepeat request acknowledgement (HARQ-ACK) payload for a first componentcarrier (CC) set based at least on a first downlink assignment index(DAI); determining a second HARQ-ACK payload for a second CC set basedat least on a second DAI; and transmitting the first HARQ-ACK payloadfor the first CC set and the second HARQ-ACK payload for the second CCset, wherein at least one CC is assigned to the first CC set or thesecond CC set based at least on a semi-static code block groupconfiguration for the at least one CC, wherein the first HARQ-ACKpayload for the first CC set is concatenated in a first HARQ-ACK payloadgroup and the second HARQ-ACK payload for the second CC set isconcatenated in a second HARQ-ACK payload group, and wherein the firstHARQ-ACK payload group and the second HARQ-ACK payload group areconcatenated with one another for transmission.
 2. The method of claim1, wherein one or more first CCs included in the first CC set areassociated with a first code block group (CBG) configuration, andwherein one or more second CCs included in the second CC set areassociated with a second CBG configuration that is different from thefirst CBG configuration.
 3. The method of claim 2, wherein the first CBGconfiguration is a configuration where CBGs are enabled and the secondCBG configuration is a configuration where CBGs are disabled.
 4. Themethod of claim 1, wherein at least one different CC is assigned to thefirst CC set or the second CC set based at least on a dynamic code blockgroup configuration, for the at least one different CC, indicated infallback downlink control information that overrides a default orsemi-static code block group configuration.
 5. The method of claim 1,wherein one or more first CCs are assigned to the first CC set and oneor more second CCs are assigned to the second CC set for a particulartransmission time interval.
 6. The method of claim 1, wherein one ormore first CCs are assigned to the first CC set and one or more secondCCs are assigned to the second CC set based at least on a determinationthat code block groups are enabled for at least one CC of the UE.
 7. Themethod of claim 1, wherein the first DAI is a first cumulative DAI andthe second DAI is a second cumulative DAI.
 8. The method of claim 1,wherein the first DAI is a first total DAI and the second DAI is asecond total DAI.
 9. The method of claim 1, wherein at least one of thefirst HARQ-ACK payload group or the second HARQ-ACK payload group ispadded with DAI padding prior to concatenation with one another.
 10. Themethod of claim 1, wherein a size of the first HARQ-ACK payload isdifferent from a size of the second HARQ-ACK payload.
 11. The method ofclaim 1, further comprising: transmitting a first size indicator thatindicates a first size of the first HARQ-ACK payload and a second sizeindicator that indicates a second size of the second HARQ-ACK payload.12. A user equipment (UE) for wireless communication, comprising:memory; and one or more processors operatively coupled to the memory,the memory and the one or more processors configured to: determine afirst hybrid automatic repeat request acknowledgement (HARQ-ACK) payloadfor a first component carrier (CC) set based at least on a firstdownlink assignment index (DAI); determine a second HARQ-ACK payload fora second CC set based at least on a second DAI; and transmit the firstHARQ-ACK payload for the first CC set and the second HARQ-ACK payloadfor the second CC set, wherein at least one CC is assigned to the firstCC set or the second CC set based at least on a semi-static code blockgroup configuration for the at least one CC, wherein the first HARQ-ACKpayload for the first CC set is concatenated in a first HARQ-ACK payloadgroup and the second HARQ-ACK payload for the second CC set isconcatenated in a second HARQ-ACK payload group, and wherein the firstHARQ-ACK payload group and the second HARQ-ACK payload group areconcatenated with one another for transmission.
 13. The UE of claim 12,wherein one or more first CCs included in the first CC set areassociated with a first code block group (CBG) configuration, andwherein one or more second CCs included in the second CC set areassociated with a second CBG configuration that is different from thefirst CBG configuration.
 14. The UE of claim 13, wherein the first CBGconfiguration is a configuration where CBGs are enabled and the secondCBG configuration is a configuration where CBGs are disabled.
 15. The UEof claim 12, wherein at least one different CC is assigned to the firstCC set or the second CC set based at least on a dynamic code block groupconfiguration, for the at least different one CC, indicated in fallbackdownlink control information that overrides the semi-static code blockgroup configuration.
 16. The UE of claim 12, wherein one or more firstCCs are assigned to the first CC set and one or more second CCs areassigned to the second CC set for a particular transmission timeinterval.
 17. The UE of claim 12, wherein one or more first CCs areassigned to the first CC set and one or more second CCs are assigned tothe second CC set based at least on a determination that code blockgroups are enabled for at least one CC of the UE.
 18. The UE of claim12, wherein the first DAI includes at least one of a first cumulativeDAI or a first total DAI, and wherein the second DAI includes at leastone of a second cumulative DAI or a second total DAI.
 19. The UE ofclaim 12, wherein at least one of the first HARQ-ACK payload group orthe second HARQ-ACK payload group is padded with DAI padding prior toconcatenation with one another.
 20. The UE of claim 12, wherein a sizeof the first HARQ-ACK payload is different from a size of the secondHARQ-ACK payload.
 21. The UE of claim 12, wherein the one or moreprocessors are further configured to: transmit a first size indicatorthat indicates a first size of the first HARQ-ACK payload and a secondsize indicator that indicates a second size of the second HARQ-ACKpayload.
 22. A non-transitory computer-readable medium storinginstructions for wireless communication, the instructions comprising:one or more instructions that, when executed by one or more processorsof a user equipment (UE), cause the one or more processors to: determinea first hybrid automatic repeat request acknowledgement (HARQ-ACK)payload for a first component carrier (CC) set based at least on a firstdownlink assignment index (DAI); determine a second HARQ-ACK payload fora second CC set based at least part on a second DAI; and transmit thefirst HARQ-ACK payload for the first CC set and the second HARQ-ACKpayload for the second CC set, wherein at least one CC is assigned tothe first CC set or the second CC set based at least on a semi-staticcode block group configuration for the at least one CC, wherein thefirst HARQ-ACK payload for the first CC set is concatenated in a firstHARQ-ACK payload group and the second HARQ-ACK payload for the second CCset is concatenated in a second HARQ-ACK payload group, and wherein thefirst HARQ-ACK payload group and the second HARQ-ACK payload group areconcatenated with one another for transmission.
 23. The non-transitorycomputer-readable medium of claim 22, wherein one or more first CCsincluded in the first CC set are associated with a first code blockgroup (CBG) configuration, and wherein one or more second CCs includedin the second CC set are associated with a second CBG configuration thatis different from the first CBG configuration.
 24. The non-transitorycomputer-readable medium of claim 23, wherein the first CBGconfiguration is a configuration where CBGs are enabled and the secondCBG configuration is a configuration where CBGs are disabled.
 25. Thenon-transitory computer-readable medium of claim 22, wherein at leastone different CC is assigned to the first CC set or the second CC setbased at least on a dynamic code block group configuration, for the atleast one different CC, indicated in fallback downlink controlinformation that overrides the semi-static code block groupconfiguration.
 26. The non-transitory computer-readable medium of claim22, wherein one or more first CCs are assigned to the first CC set andone or more second CCs are assigned to the second CC set based at leaston a determination that code block groups are enabled for at least oneCC of the UE.
 27. The non-transitory computer-readable medium of claim22, wherein the first DAI includes at least one of a first cumulativeDAI or a first total DAI, and wherein the second DAI includes at leastone of a second cumulative DAI or a second total DAI.
 28. Thenon-transitory computer-readable medium of claim 22, wherein at leastone of the first HARQ-ACK payload group or the second HARQ-ACK payloadgroup is padded with DAI padding prior to concatenation with oneanother.
 29. The non-transitory computer-readable medium of claim 22,wherein a size of the first HARQ-ACK payload is different from a size ofthe second HARQ-ACK payload.
 30. The non-transitory computer-readablemedium of claim 22, wherein the instructions further comprise: one ormore instructions to transmit a first size indicator that indicates afirst size of the first HARQ-ACK payload and a second size indicatorthat indicates a second size of the second HARQ-ACK payload.
 31. Anapparatus for wireless communication, comprising: means for determininga first hybrid automatic repeat request acknowledgement (HARQ-ACK)payload for a first component carrier (CC) set based at least on a firstdownlink assignment index (DAI); means for determining a second HARQ-ACKpayload for a second CC set based at least on a second DAI; and meansfor transmitting the first HARQ-ACK payload for the first CC set and thesecond HARQ-ACK payload for the second CC set, wherein at least one CCis assigned to the first CC set or the second CC set based at least on asemi-static code block group configuration for the at least one CC,wherein the first HARQ-ACK payload for the first CC set is concatenatedin a first HARQ-ACK payload group and the second HARQ-ACK payload forthe second CC set is concatenated in a second HARQ-ACK payload group,and wherein the first HARQ-ACK payload group and the second HARQ-ACKpayload group are concatenated with one another for transmission. 32.The apparatus of claim 31, wherein one or more first CCs included in thefirst CC set are associated with a first code block group (CBG)configuration, and wherein one or more second CCs included in the secondCC set are associated with a second CBG configuration that is differentfrom the first CBG configuration.
 33. The apparatus of claim 32, whereinthe first CBG configuration is a configuration where CBGs are enabledand the second CBG configuration is a configuration where CBGs aredisabled.
 34. The apparatus of claim 31, wherein at least one differentCC is assigned to the first CC set or the second CC set based at leaston a dynamic code block group configuration, for the at least onedifferent CC, indicated in fallback downlink control information thatoverrides the semi-static code block group configuration.
 35. Theapparatus of claim 31, wherein one or more first CCs are assigned to thefirst CC set and one or more second CCs are assigned to the second CCset for a particular transmission time interval.
 36. The apparatus ofclaim 31, wherein one or more first CCs are assigned to the first CC setand one or more second CCs are assigned to the second CC set based atleast on a determination that code block groups are enabled for at leastone CC of the apparatus.
 37. The apparatus of claim 31, wherein thefirst DAI includes at least one of a first cumulative DAI or a firsttotal DAI, and wherein the second DAI includes at least one of a secondcumulative DAI or a second total DAI.
 38. The apparatus of claim 31,wherein the first HARQ-ACK payload group or the second HARQ-ACK payloadgroup is padded with DAI padding prior to concatenation with oneanother.
 39. The apparatus of claim 31, wherein a size of the firstHARQ-ACK payload is different from a size of the second HARQ-ACKpayload.
 40. The apparatus of claim 31, further comprising: means fortransmitting a first size indicator that indicates a first size of thefirst HARQ-ACK payload and a second size indicator that indicates asecond size of the second HARQ-ACK payload.